Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D498/00—Heterocyclic compounds containing in the condensed system at least one hetero ring having nitrogen and oxygen atoms as the only ring hetero atoms
  • C07D498/02—Heterocyclic compounds containing in the condensed system at least one hetero ring having nitrogen and oxygen atoms as the only ring hetero atoms in which the condensed system contains two hetero rings
  • C07D498/04—Ortho-condensed systems
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D261/00—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings
  • C07D261/02—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings not condensed with other rings
  • C07D261/06—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings not condensed with other rings having two or more double bonds between ring members or between ring members and non-ring members
  • C07D261/10—Heterocyclic compounds containing 1,2-oxazole or hydrogenated 1,2-oxazole rings not condensed with other rings having two or more double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D261/14—Nitrogen atoms

Definitions

• This invention relates to new isoXazolo[5,4-b]pyridine- 5-carboxylic acids and esters, and salts thereof.
• These new compounds have the general formula (1) R2 N Ra COOR R and R each is hydrogen or lower alkyl.
• R2 N Ra COOR R and R each is hydrogen or lower alkyl.
• the basic nitrogen group DETAILED DESCRIPTION OF THE INVENTION The symbols have the following meanings in Formula I and throughout this specification.
• R and R each is hydrogen or lower alkyl.
• the basic nitrogen group is an acyclic amino group wherein R and R each is hydrogen, lower alkyl, phenyl, substituted phenyl (i.e., the phenyl ring contains one or two simple substituents including halogen or trifluoromethyl), phenyl-lower alkylene or di-lower alkylamino-lower alkylene (preferably there is only one of these substituents).
• This basic group may also form a heterocycle of 3-, 5- o G-members in which an additional nitrogen is present, in particular, the aziridinyl, pyrrolidino, piperidino, pyrazolyl, pyrimidinyl, pyridazinyl or piperazinyl radicals, each of which may also bear as a substituent at hydroxy-lower alkyl group or one or two lower alkyl groups.
• R and R each is hydrogen, R ,R -phenyl (wherein R and R each is hydrogen, halogen or trifluoromethyl), phenyl-lower alkylene, or di-lower alkylamino-lower alkylene or R and R together with the nitrogen to which they are attached form one of the heterocycles mentioned above or the R monosubstituted or R 'R -disubstituted derivative (wherein R and R are the substituents lower alkyl or hydroxy-lower alkyl in addition to hydrogen).
• the lower alkyl and lower alkylene groups in any of the foregoing radicals are straight or branched chain hydrocarbon groups of up to eight carbon atoms like methyl, ethyl, propyl, isopropyl, butyl, t-butyl and the like. The lowest four members are preferred. Benzyl and phenethyl are the preferred phenyl-lower alkylene groups. All four halogens are included, but chlorine is preferred.
• the new compounds of Formula I are prepared from compounds of the formula wherein X is chlorine or bromine.
• This reaction is effected by treating the reactants either at room temperature or at an elevated temperature. In some cases it may be advantageous to make use of an autoclave.
• a S-aminoisoxazole of the formula (V) RFQQJLNHQ (produced by reacting 3-iminobntyronitrile with hydroxylamine by the procedure described in Ann. Chem. 624, 22 (1959) is made to react with an alkoxyrnethylene malonic acid ester of the formula C O -alkyl by heating at a temperature of about 120 C.
• this 4-hydroxy compound may be refluxed for several hours with a phosphorus halide like phosphorus oxychloride to obtain the intermediate of Formula III.
• the compounds of Formula I form salts which are also part of this invention.
• the salts include acid-addition salts, particularly the non-toxic, physiologically acceptable members.
• the bases of Formula I form salts by reaction with a variety of inorganic and organic acids providing acid addition salts including, for example, hydrohalides (especially the hydrochloride and hydrobromide), sulfate, nitrate, phosphate, oxalate, tartrate, malate, citrate, picrate, acetate, ascorbate, succinate, arylsulfonates like benzenesulfonate, toluenesulfonate, alkanesulfonates like methanesulfonate, cyclohexanesulfamate, etc.
• hydrohalides especially the hydrochloride and hydrobromide
• sulfate nitrate
• phosphate oxalate
• tartrate malate
• citrate citrate
• picrate acetate
• the acid addition salts frequently provide a convenient means for isolating the product, e.g., by forming and precipitating the salt in an appropriate menstruum in which the salt is insoluble, then after separation of the salt, neutralizing with a base such as barium hydroxide or sodium hydroxide, to obtain the free base of Formula I.
• a base such as barium hydroxide or sodium hydroxide
• Other salts may then be formed from the free base by reaction with an equivalent of acid.
• the new compounds of this invention are central nervous system depressants and may be used as tranquilizers or ataractic agents for the relief of anxiety and tension states, for example, in mice, cats, rats, dogs and other mammalian species, in the same manner as chlordiazepoxide.
• a compound or mixture of compounds of Formula I, or non-toxic, physiologically acceptable acid addition salt thereof may be administered orally or parenterally in a conventional dosage form such as tablet, capsule, injectable or the like.
• These may be conventionally formulated in an oral or parenteral dosage form by compounding about to 250 mg. per unit of dosage with conventional vehicle,
• excipient binder, preservative, stabilizer, flavor or the like as called for by accepted pharmaceutical practice.
• the new compounds also increase the intracellular concentration of adenosine-3',5'-cyclic monophosphate, and thus by the administration of about 1 to 100 mg./kg./ day, preferably about 10 to 50 mg./-kg., in single or two to four divided doses in conventional oral or parenteral dosage forms such as those described above may be used to alleviate the symptoms of asthma.
• EXAMPLE 1 4-n-buty1amino-5-ethoxycarbonyl-3-methylisoxazolo [5,4-b]pyridine (a) (3-methyl 5 isoxazolyl)aminomethylenemalonic acid diethyl ester.112.5 g. of 3-methyl-5-aminoisoxazole (1.14 mol.) and 248 g. of ethoxymethylenemalonic acid diethyl ester (1.14 mol.) are heated with stirring for 45 minutes at 130. After this period, ethanol is removed under reduced pressure. The residue solidifies on cooling and is recrystallized from ethanol, M.P. 134-136, yield 245 g.
• the hydrochloride of 4-n-butylamino-5-ethoxycarbonyl- B-methylisoxazolo[5,4-b]pyridine is formed by adding to a solution of the above product an alcoholic solution of hydrogen chloride.
• a compound of the formula /Rr IIP-Rs N l o N wherein R and R each is hydrogen or lower alkyl, R and R each is hydrogen, lower alkyl, R or one of said terms is R -phenyl, phenyl-lower alkylene, di-lower alkylamino-lower alkylene or R and R together with the nitrogen to which they are attached form one of the heterocyclics R R -aziridinyl, R R -pyrrolidino, R is hydrogen, R is hydrogen, halogen or trifiuoromethyl, and R and R each is hydrogen or lower alkyl providing that only one R is a phenyl-containing substituent, and physiologically acceptable acid addition salts thereof.
• R is hydrogen, and R, R and R each is lower alkyl.
• R and R each is hydrogen, R is methyl and R is phenyl.
• R is ethyl, R is methyl, R is hydrogen and R is (trifluoromethyl) phenyl.
• R is ethyl, R is methyl, R is dichlorophenyl and R is hydrogen.
• R is ethyl, R is methyl, R is di(lower alkyl)amino(lower alkylene) and R is hydrogen.
• a compound as in claim 9 wherein the R group is dimethylaminopropyl.
• R8 is pyrrolidino.
• ALAN L. ROTMAN Primary Examiner References Clted CL XR. UNITED STATES PATENTS 10 260-250 A, 268 BC, 256.4 R, 293.58, 294.8 c; 424- 3,669,950 6/1'972 Hoehn et a1.
• 260-29S.5B 251, 266, 267

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Nitrogen And Oxygen Or Sulfur-Condensed Heterocyclic Ring Systems (AREA)
• Heterocyclic Carbon Compounds Containing A Hetero Ring Having Nitrogen And Oxygen As The Only Ring Hetero Atoms (AREA)
• Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

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Publications (1)

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Family Applications (1)

Country Status (7)

Cited By (5)

• 1971
  • 1971-03-29 US US00129199A patent/US3736326A/en not_active Expired - Lifetime
• 1972
  • 1972-03-01 GB GB958672A patent/GB1374916A/en not_active Expired
  • 1972-03-16 CA CA137,234A patent/CA970376A/en not_active Expired
  • 1972-03-17 DE DE19722213076 patent/DE2213076A1/de active Pending
  • 1972-03-20 HU HUSU723A patent/HU162889B/hu unknown
  • 1972-03-27 CH CH452172A patent/CH545810A/xx not_active IP Right Cessation
  • 1972-03-29 FR FR7211055A patent/FR2132189B1/fr not_active Expired

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